Highly effective chemosensor for mercury ions based on bispyrenyl derivative.

A new bispyrenyl azadiene derivative has been synthesized and examined for its cation recognition abilities toward different cations. The ligand shows strong affinity for Hg(2+) ions over other cations such as Cu(2+), Pb(2+), Zn(2+), Ni(2+), Cd(2+), Ag(+), K(+), Na(+) and Li(+). An "Off-On" type of fluorescent behaviour was observed with simultaneous presence of Cu(2+) and Hg(2+) ions. An ion selective electrode (ISE) is also formed which showed excellent selectivity to Hg(2+) over all the other cations tested. The lower limit of detection is 7.08 x 10(-6) M.

Fluorescence turn-on sensors for HSO4-.

A coumarin-based derivative (1), a highly selective and sensitive turn-on fluorogenic probe for the detection of HSO4- ions in aqueous solution, has been designed and synthesized. Various spectroscopic and DFT calculations revealed that H-bonding between the phenolic -OH and imine nitrogen of 1 played a crucial role in its high selectivity for HSO4-.

Two-year follow-up of the phase II marker lesion study of intravesical apaziquone for patients with non-muscle invasive bladder cancer.

OBJECTIVES: To study the time-to-recurrence and duration of response in non-muscle invasive bladder cancer (NMIBC) patients, with a complete ablative response after intravesical apaziquone instillations. METHODS: Transurethral resection of bladder tumour(s) (TURBT) was performed in patients with multiple pTa-T1 G1-2 urothelial cell carcinoma (UCC) of the bladder, with the exception of one marker lesion of 0.5-1.0 cm. Intravesical apaziquone was administered at weekly intervals for six consecutive weeks, without maintenance instillations. A histological confirmed response was obtained 2-4 weeks after the last instillation. Routine follow-up (FU) was carried out at 6, 9, 12, 18 and 24 months from the first apaziquone instillation. RESULTS: At 3 months FU 31 of 46 patients (67.4%) had a complete response (CR) to ablative treatment. Side-effects on the long-term were only mild. Two CR patients dropped out during FU. On intention-to-treat (ITT) analysis 49.5% of the CR patients were recurrence-free at 24 months FU, with a median duration of response of 18 months. Of 15 no response (NR) patients, only two received additional prophylactic instillations after TURBT. On ITT-analysis 26.7% of the NR patients were recurrence-free (log rank test, P = 0.155). The overall recurrence-free survival was 39% (18 of 46 patients) at 24 months FU. CONCLUSIONS: The CR of the marker lesion in 67% of patients was followed by a recurrence-free rate of 56.5% at 1-year FU, and 49.5% at 2-year FU. These long-term results are good in comparison with the results of other ablative studies.

Response of multiple recurrent TaT1 bladder cancer to intravesical apaziquone (EO9): comparative analysis of tumor recurrence rates.

OBJECTIVES: Previous studies have demonstrated that intravesical administration of apaziquone (EOquin) has ablative activity against superficial bladder cancer marker lesions with 8 out of 12 complete responses recorded. We present a comparison between the rates of tumor recurrence before and after treatment with apaziquone. METHODS: The rate of tumor recurrence after treatment with apaziquone was compared with each patient's historical record of recurrences obtained from a retrospective analysis of the patients' case notes. The time to each recurrence event before apaziquone treatment and the time to the first recurrence after apaziquone treatment were recorded, and the data were analyzed using a population-averaged linear regression model using Stata Release, version 9.2, software. RESULTS: Of the eight complete responses obtained in the Phase I study, tumor recurrence occurred in 4 patients and the remaining 4 patients remained disease free after a median follow-up of 31 months. The time to the first recurrence after apaziquone treatment was significantly longer (P <0.001) compared with the historical pattern and recurrence interval before apaziquone. Before apaziquone instillation, the mean +/- SE recurrence rate and tumor rate per year was 1.5 +/- 0.2 and 4.8 +/- 1.2, respectively, and these decreased to 0.6 +/- 0.25 and 1.5 +/- 0.8, respectively, after apaziquone treatment (P <0.05). CONCLUSIONS: The results of this study indicate that early recurrences after treatment with apaziquone are infrequent and the interval to recurrence is significantly greater compared with the historical recurrence times for these patients. Larger prospective randomised trials are warranted to confirm these results.

Highly selective potentiometric determination of mercury(II) ions using 1-furan-2-yl-4-(4-nitrophenyl)-2-phenyl-5H-imidazole-3-oxide based membrane electrodes.

The electrode characteristics and selectivities of PVC-based mercury(II) selective coated graphite electrode (CGE) and polymeric membrane electrode (PME) incorporating the recently synthesized 1-furan-2-yl-4-(4-nitrophenyl)-2-phenyl-5H-imidazole-3-oxide are reported here. The electrodes exhibit Nernstian slope for mercury(II) ions over wide concentration ranges, i.e. 1.0 x 10(-1)M to 1.0 x 10(-6)M (with CGE) and 1.0 x 10(-1)M to 1.0 x 10(-5)M (with PME). The lower detection limits shown by CGE and PME are 8.91 x 10(-7)M and 6.30 x 10(-6)M, respectively, in the pH range of 1.0-4.0. From the comparative study of these electrodes, CGE has been found to be better than PME in terms of lower detection limit and better selectivity for mercury(II) ions with comparatively less interference from silver(I) ions. The proposed electrodes can be successfully used as an indicator electrode for potentiometric titration of mercury with potassium dichromate. The electrodes have been successfully applied for estimation of mercury content in synthetic water samples, insecticide (parad tablet) and dental amalgam.

Secondary penile tumours revisited.

OBJECTIVE: To highlight the salient features of metastatic malignancies involving the penis, with special reference to the primary tumour sites, metastatic mechanisms, clinical features, differential diagnosis, treatment and prognosis. METHODS: A comprehensive search of the literature was performed using MEDLINE and EMBASE, using the keywords 'penis', 'secondary malignancy', 'metastasis' and 'malignant priapism' to identify reviews and case reports of secondary penile malignancy. A case of rare clinical presentation of metastatic penile lesion is presented along with the review of the literature. CONCLUSION: Secondary malignancy of the penis is a rare clinical entity, despite the rich vascularisation of this organ. The majority of metastatic lesions take their origin from the neighbouring genito-urinary organs, mainly prostate and bladder. These lesions are often associated with disseminated malignancy and hence have a poor outcome. Nodular or ulcerative lesions involving the corpora cavernosa or priapism are the main modes of clinical presentation. In most cases, only palliative or supportive therapy is indicated.

Phase I/II pilot study of intravesical apaziquone (EO9) for superficial bladder cancer.

PURPOSE: The quinone based bioreductive drug apaziquone (EO9) failed to demonstrate efficacy in previous phase II studies following intravenous administration. We determined the dose of apaziquone that can be safely administered intravesically and explored its activity for superficial bladder transitional cell carcinoma. MATERIALS AND METHODS: Six patients with multifocal, Ta/T1 and G1/G2 transitional cell carcinoma of the bladder received escalating doses of apaziquone formulated as EOquintrade mark (0.5 mg/40 ml up to 16 mg/40 ml) weekly for 6 weeks. A further 6 patients received weekly apaziquone at the highest nontoxic dose established. Pharmacokinetic parameters were determined in urine and blood, and the pharmacodynamic markers NQO1 (reduced nicotinamide adenine dinucleotide phosphate:quinone oxidoreductase-1) and glucose transporter 1 were also characterized. Efficacy was determined against a marker lesion. RESULTS: Local toxicity (grades 2 and 3 dysuria, and hematuria) was observed at doses of 8 mg/40 ml and above but 4 mg/40 ml was well tolerated with no systemic or local side effects. Apaziquone in urine increased linearly with the dose but no apaziquone was detected in plasma. In 8 of 12 patients complete macroscopic and histological disappearance of the marker lesion occurred. A correlation between response and NQO1 and/or glucose transporter 1 expression could not be established. CONCLUSIONS: Intravesical administration of 4 mg/40 ml apaziquone was well tolerated and had ablative activity against superficial bladder cancer marker lesions.

Phase II marker lesion study with intravesical instillation of apaziquone for superficial bladder cancer: toxicity and marker response.

PURPOSE: We studied the ablative activity of intravesical apaziquone (EOquin) on a papillary marker tumor and determined the incidence of side effects. MATERIALS AND METHODS: A total of 46 patients with multiple pTa or pT1 bladder tumors underwent visible lesion resection except for 1 marker tumor. Patients were then treated with 6 instillations of apaziquone at weekly intervals. The response was determined 2 to 4 weeks after the last instillation. RESULTS: One patient withdrew informed consent and refused the last treatment due to side effects. A histologically proven complete response was seen in 30 patients. Progression to invasive stage was not observed. Local side effects in this study were comparable to those due to other chemotherapy instillations, such as mitomycin C and epirubicin, but less severe and less frequent compared to those of bacillus Calmette-Guerin instillations. CONCLUSIONS: The histological complete response rate after 6 consecutive instillations of apaziquone in patients with superficial bladder cancer was 67% (95% CI 51 to 80). Local side effects were comparable to side effects due to other chemotherapy instillations.

Chemo-prevention in superficial bladder cancer using mitomycin C: a survey of the practice patterns of British urologists.

OBJECTIVE: To assess the use of mitomycin C, by urologists within the UK, as a single-dose intravesical agent. Current European recommendations are to use one dose after any new tumour resection. METHODS: We assessed the current patterns of mitomycin C usage amongst British urologists, particularly with reference to one instillation after resecting a new bladder tumour, hypothesizing that British urologists would use mitomycin C in line with current guidelines. A one-page questionnaire was mailed to 527 consultant urologists in the UK enquiring about their use of mitomycin C in superficial bladder cancer. A second mailing was sent to encourage nonresponders. RESULTS: Of the 527 consultants, 320 (61%) replied, of which 313 (59%) questionnaires were evaluable. Of these 313 respondents, 299 (95%) used mitomycin C; 244 respondents (82%) advocated the use of one dose of mitomycin C after resecting a new tumour, but only 10 (4%) would use it immediately after tumour resection and 155 (64%) use it within 24 h. Most (98%) respondents favoured the use of a mitomycin C course after resecting multiple tumours or after multiple recurrences. Interestingly, 20 respondents (7%) would use mitomycin C as a first-line therapy for carcinoma in situ and a further 23 (8%) would use it for G3T1 tumours. A minority (14%) would use it after nephrectomy for upper tract transitional cell carcinoma. Almost all respondents indicated a dose of 40 mg in 40 mL of diluent. Maintenance treatment with mitomycin C was advocated by 44 (15%) of respondents, mainly for recurrent multifocal Ta/T1 tumours. The perception of the side-effects of mitomycin C was favourable, with 69% of respondents judging mitomycin C to be well tolerated with mild side-effects. CONCLUSION: Urologists adopt new ideas rapidly, as shown by the wide acceptance of the UK Medical Research Council study. The prompt use of mitomycin C needs to be reinforced, as efficacy is optimum within 6 h of resection. A few consultants persist in continuing with established practices, which have little evidence base. The publication of such survey results, with guidelines for treatment, should encourage those urologists whose practice is at variance from the norm to reflect on and change their practice.

NAD(P)H:Quinone oxidoreductase-1 C609T polymorphism analysis in human superficial bladder cancers: relationship of genotype status to NQO1 phenotype and clinical response to Mitomycin C.

NAD(P)H:Quinone oxidoreductase-1 (NQO1) has been implicated in the bioreductive activation of the clinically active anticancer drug Mitomycin C (MMC) and a polymorphic variant of NQO1 which lacks functional enzyme activity (NQO1*2) has been linked with poor survival in patients treated with MMC. The relationship between NQO1 activity and cellular response to MMC is however controversial and the aim of this study was to determine whether the response of bladder cancer patients to MMC can be forecast on the basis of NQO1*2 genotype status. Genomic DNA was extracted from formalin-fixed, paraffin-embedded tissue from 148 patients with low to intermediate grade (G1/G2) superficial (Ta/T1) bladder cancers and NQO1*2 genotype status determined by PCR-RFLP. NQO1*2 genotype status was retrospectively compared with clinical response to intravesical administered MMC with the primary end-point being time to first recurrence. NQO1 phenotype was determined by immunohistochemistry. Of the 148 patients genotyped, 85 (57.4%) were NQO1*1 (wild-type), 59 (39.8%) were NQO1*1/*2 (heterozygotes) and 4 (2.7%) were NQO1*2/*2. No NQO1 protein expression was detected in NQO1*2/*2 tumours. A broad spectrum of NQO1 protein expression existed in tumours genotyped as NQO1*1 and NQO1*1/*2 although tumours with NQO1*1 typically expressed higher NQO1 protein. A poor correlation existed between NQO1*2 genotype status and clinical response to MMC. The results of this retrospective study suggest that tailoring MMC therapy to individual patients with superficial bladder cancer on the basis of NQO1 genotype status is unlikely to be of clinical benefit.

Immunohistochemical analysis of NAD(P)H:quinone oxidoreductase and NADPH cytochrome P450 reductase in human superficial bladder tumours: relationship between tumour enzymology and clinical outcome following intravesical mitomycin C therapy.

A central theme within the concept of enzyme-directed bioreductive drug development is the potential to predict tumour response based on the profiling of enzymes involved in the bioreductive activation process. Mitomycin C (MMC) is the prototypical bioreductive drug that is reduced to active intermediates by several reductases including NAD(P)H:quinone oxidoreductase (NQO1) and NADPH cytochrome P450 reductase (P450R). The purpose of our study was to determine whether NQO1 and P450R protein expression in a panel of low-grade, human superficial bladder tumours correlates with clinical response to MMC. A retrospective clinical study was conducted in which the response to MMC of 92 bladder cancer patients was compared to the immunohistochemical expression of NQO1 and P450R protein in archived paraffin-embedded bladder tumour specimens. A broad spectrum of NQO1 protein levels exists in bladder tumours between individual patients, ranging from intense to no immunohistochemical staining. In contrast, levels of P450R were similar with most tumours having moderate to high levels. All patients were chemotherapy naïve prior to receiving MMC and clinical response was defined as the time to first recurrence. A poor correlation exists between clinical response and NQO1, P450R or the expression patterns of various combinations of the 2 proteins. The results of our study demonstrate that the clinical response of superficial bladder cancers to MMC cannot be predicted on the basis of NQO1 and/or P450R protein expression and suggest that other factors (other reductases or post DNA damage events) have a significant bearing on tumour response.

Detection of (NAD(P)H:Quinone oxidoreductase-1, EC 1.6.99.2) 609C-->T and 465C-->T polymorphisms in formalin-fixed, paraffin-embedded human tumour tissue using PCR-RFLP.

NQO1 is a cytosolic flavoprotein that plays a dual role in the detoxification of potentially carcinogenic compounds and the bioreductive activation of quinone based anticancer drugs. Two polymorphic variants of NQO1 exist (NQO1*2 and NQO1*3) which cause significant phenotypic reductions in NQO1 protein content and activity. Current methods for detecting NQO1 polymorphisms commonly use PCR-RFLP techniques and have exclusively used DNA isolated from fresh tissues. This study describes a method that is suitable for analysing NQO1 polymorphisms in genomic DNA isolated from formalin-fixed paraffin-embedded tissue. The method utilises two rounds of PCR amplification using a nested primer strategy that generates specific PCR products followed by RFLP analysis using either Hinf1 (for NQO1*2) or Msp1 (for NQO1*3). Whilst existing methods proved unsatisfactory (low product yield and poor specificity), the nested primer strategy produced good quality PCR products suitable for RFLP analysis and genotyping of NQO1*2 and NQO1*3 in archival tissue samples. The ability to utilise the vast archives of human tissue held by pathology laboratories would be of considerable benefit as retrospective studies comparing NQO1 genotype status, patient history and treatment outcomes could be conducted.